Enhanced Optical Conductivity Induced by Surface States in ABC-stacked Few-Layer Graphene

• Main Authors: Yan, Jia-An, Ruan, W. Y, Chou, M. Y
• Format: Journal Article
• Language: English
• Published: 03-06-2011
• Subjects: Physics - Materials Science; Physics - Mesoscale and Nanoscale Physics
• DOI: 10.48550/arxiv.1106.0554

Phys. Rev. B 83, 245418 (2011) The surface states of ABC-stacked few-layer graphene (FLG) are studied based
on density-functional theory. These states form flat bands near the Fermi
level, with the k-space range increasing with the layer number. Based on a
tight-binding model, the characteristics of these surface states and their
evolution with respect to the number of layers are examined. The infrared
optical conductivity is then calculated within the single-particle excitation
picture. We show that the surface states introduce unique peaks at around 0.3
eV in the optical conductivity spectra of ABC-stacked FLG when the polarization
is parallel to the sheets, in good agreement with recent experimental
measurement. Furthermore, as the layer number increases, the absorption
amplitude is greatly enhanced and the peak position red-shifts, which provides
a feasible way to identify the number of layers for ABC-stacked FLG using
optical conductivity measurements.